fru_walk_tree
status = fru_walk_tree(frutree, "", process_node, NULL);
status = fru_walk_tree(frutree, "", process_matching_node,
extern fru_errno_t fru_walk_tree(fru_nodehdl_t node, const char *prior_path,
status = fru_walk_tree(next, path, process_node, args);
status = fru_walk_tree(next, prior_path, process_node, args);